@@ -353,7 +353,7 @@ class _FuncPtr(_CFuncPtr):
             self._handle = handle
 
     def __repr__(self):
-        return "<%s '%s', handle %x at %x>" % \
+        return "<%s '%s', handle %x at %#x>" % \
                (self.__class__.__name__, self._name,
                 (self._handle & (_sys.maxsize*2 + 1)),
                 id(self) & (_sys.maxsize*2 + 1))
 
@@ -136,7 +136,7 @@ def repr_instance(self, x, level):
             # Bugs in x.__repr__() can cause arbitrary
             # exceptions -- then make up something
         except Exception:
-            return '<%s instance at %x>' % (x.__class__.__name__, id(x))
+            return '<%s instance at %#x>' % (x.__class__.__name__, id(x))
         if len(s) > self.maxother:
             i = max(0, (self.maxother-3)//2)
             j = max(0, self.maxother-3-i)
 
@@ -123,7 +123,7 @@ def test_instance(self):
         eq(r(i2), expected)
 
         i3 = ClassWithFailingRepr()
-        eq(r(i3), ("<ClassWithFailingRepr instance at %x>"%id(i3)))
+        eq(r(i3), ("<ClassWithFailingRepr instance at %#x>"%id(i3)))
 
         s = r(ClassWithFailingRepr)
         self.assertTrue(s.startswith("<class "))
 
@@ -1536,6 +1536,14 @@ def __eq__(self, other):
         self.assertEqual(len(d), 0)
         self.assertEqual(count, 2)
 
+    def test_make_weak_valued_dict_repr(self):
+        dict = weakref.WeakValueDictionary()
+        self.assertRegex(repr(dict), '<WeakValueDictionary at 0x.*>')
+
+    def test_make_weak_keyed_dict_repr(self):
+        dict = weakref.WeakKeyDictionary()
+        self.assertRegex(repr(dict), '<WeakKeyDictionary at 0x.*>')
+
 from test import mapping_tests
 
 class WeakValueDictionaryTestCase(mapping_tests.BasicTestMappingProtocol):
 
@@ -287,7 +287,7 @@ def test_datetime_datetime(self):
     def test_repr(self):
         d = datetime.datetime(2007,1,2,3,4,5)
         t = xmlrpclib.DateTime(d)
-        val ="<DateTime '20070102T03:04:05' at %x>" % id(t)
+        val ="<DateTime '20070102T03:04:05' at %#x>" % id(t)
         self.assertEqual(repr(t), val)
 
     def test_decode(self):
 
@@ -144,7 +144,7 @@ def __contains__(self, key):
         return o is not None
 
     def __repr__(self):
-        return "<WeakValueDictionary at %s>" % id(self)
+        return "<WeakValueDictionary at %#x>" % id(self)
 
     def __setitem__(self, key, value):
         if self._pending_removals:
@@ -348,7 +348,7 @@ def __len__(self):
         return len(self.data) - len(self._pending_removals)
 
     def __repr__(self):
-        return "<WeakKeyDictionary at %s>" % id(self)
+        return "<WeakKeyDictionary at %#x>" % id(self)
 
     def __setitem__(self, key, value):
         self.data[ref(key, self._remove)] = value
 
@@ -354,7 +354,7 @@ def __str__(self):
         return self.value
 
     def __repr__(self):
-        return "<DateTime %r at %x>" % (self.value, id(self))
+        return "<DateTime %r at %#x>" % (self.value, id(self))
 
     def decode(self, data):
         self.value = str(data).strip()
@@ -846,7 +846,7 @@ def __init__(self, server):
         self.__call_list = []
 
     def __repr__(self):
-        return "<MultiCall at %x>" % id(self)
+        return "<MultiCall at %#x>" % id(self)
 
     __str__ = __repr__
 
 
@@ -108,6 +108,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #22031: Reprs now always use hexadecimal format with the "0x" prefix
+  when contain an id in form " at 0x...".
+
 - Issue #22018: signal.set_wakeup_fd() now raises an OSError instead of a
   ValueError on ``fstat()`` failure.